The edges of glass sheets are conventionally finished by passing the glass sheet edges through a V-shaped groove of a grinding wheel. See in this regard, U.S. Pat. No. 6,685,541 to Brown et al (the entire content of which is expressly incorporated hereinto by reference). One major problem with conventional V-grooved grinding wheels is that over time the glass edges gouge the grinding surface creating circumferential score lines therein. If left unchecked, the grinding wheels are incapable of forming an edge bevel on the glass sheet at the desired angle. As a result, the grinding wheels must periodically be removed so that the grinding surface of the V-groove can be dressed to thereby remove the score lines and reestablish the desired taper angle, following which the grinding wheel can again be placed back into service. Suffice it to say, the removal, dressing and replacement of conventional V-grooved grinding wheels contributes to considerable equipment downtime and concomitant loss of productivity.
It would therefore be highly desirable if methods and systems could be provided which minimized equipment down time associated with redressing of grinding wheels. It would especially be desirable if a greater amount of the grinding wheel's tapered surface could be utilized before it is necessary to remove the grinding wheel for redressing. It is towards fulfilling such needs that the present invention is directed.
Broadly, the present invention is directed toward grinding methods and systems whereby the edges of a glass sheet may be beveled with minimal equipment down time. More specifically, according to the present invention methods and systems for beveling upper and lower edges along lateral sides of a glass sheet are provided. In especially preferred embodiments, the present invention includes laterally separated pairs of upper and lower edge grinding assemblies having respective upper and lower oppositely oriented tapered grinding wheels. A glass sheet may thus be moved in a generally horizontal conveyance direction between one of these pairs of upper and lower edge grinding assemblies so that respective upper or lower lateral edges of the glass sheet are brought into grinding contact therewith. Continually moving the glass sheet in the horizontal conveyance direction will therefore present the other lateral edge to the other pair of upper or lower edge grinding assemblies positioned downstream. As such, the other edge will then be beveled.
Over time, a circumferential scored groove will be formed on the tapered grinding surface of at least one of said upper and lower tapered grinding wheels. By mounting the oppositely oriented grinding wheels for independent movements both horizontally and vertically relative to the glass sheet, a fresh unscored region of the tapered grinding surface can then be presented to the glass sheet edges thereby ensuring that the proper bevel angle is achieved. This adjustable movement of the grinding wheel(s) may be further repeated until there no longer remains a meaningful amount of fresh unscored surface regions. At such time, therefore, the worn grinding wheel may be replaced so that its tapered grinding surface may be redressed. However, as compared to the duty cycle of conventional V-shaped grinding wheels, the adjustability of the grinding wheels in accordance with the present invention means that a significantly longer duty cycle can be achieved prior to grinding wheel redressing and replacement thereby enhancing productivity of the glass finishing line.
These and other aspects and advantages will become more apparent after careful consideration is given to the following detailed description of the preferred exemplary embodiments thereof.